AusBonsai

Winter has taken a toll on my pots again this year even though I don't think it has been particularly cold.
Bits just shatter off them all through winter.
Cheap prices are not so attractive now.

The sweetness of cheapness soon turns sour.

damn i thought i had it bad. thats nuts. how long had you own the pots til they started to disintegrate? I normally get at least 2 winters before they fall apart.

Many of the pots imported to Australia ( particularly the big green shed ) come from Vietnam. They are absorbent and the water will kill them eventually in every case and much sooner in frosty areas .
These low fire pots may absorb as much as 20% of their own weight in water . Stoneware , high fire pots less than 2% .
The only solution is to buy from a potter who you know fires to stoneware temperatures with stoneware clay !

Neil
im simular temps to you and ive never had any of mine crack etc. I must admit most of my pots are either European, Japanese, aussie or a higher chinese quality . I remember a while back watering some one night then having a -5 the next morning .

Are you sure the middle one didn't bust out from root growth?

These pots all came from a bonsai nursery in the northern suburbs of Melbourne. Pretty sure he said they came from a pottery owned by his family in China.
We have discussed the problems of low fired pots before so I know what the problem is and also the solution. Just posting here to let others know that cheap bonsai pots may not be the bargain you think.

Some of them last a couple of years, some crack the first winter. It appears to be far worse with the smaller pots. I have not had any problems with the larger sizes from the same source and no problem with Japanese or local pots. I will certainly have to start buying some more. The problem is finding you potters with the right pot at the right time

Are you sure the middle one didn't bust out from root growth?

That had crossed my mind, particularly as I noticed it had opened up earlier in winter. Even so, a good pot should be able to resist the roots of mondo grass.

Smaller pots do seem to make up the majority of breakages . The shape of the pot is also a factor .

Shibui, can I ask please, I’ve found a couple of vintage pots at a shop here. I’m pretty sure they are Chinese and are Guangzhou. Unfortunately both the ones I want are damaged. One had a corner chip and the other more expensive one has a crack inside the pot, but it doesn’t extend through the glaze so I assume this crack is from first firing? It’s not a small crack. Do you know anything about these pots and whether I should avoid?


Sent from my iPad using Tapatalk

Only been doing Bonsai for about six(6) years and apart from a few pots from Hachinoki, Viveanne(GBS) and Graham Cook most of the rest came from Bunnings/Masters.

I'm in Bungendore and have had only three(3) crack sufficiently to have to throw away - this year doesn't seem to have been too bad but previously -3 to -6 every couple of days in July/August is par for the course - having said this I do have a couple that have had fine hairline cracks for a few years
- these may well haunt me at a later date but what I find interesting(as regwac says) for some strange reason the shape is a factor.

Maybe a potter could provide some answer to that.

John(JP)
CBS

Shibui, can I ask please, I’ve found a couple of vintage pots at a shop here. I’m pretty sure they are Chinese and are Guangzhou. Unfortunately both the ones I want are damaged. One had a corner chip and the other more expensive one has a crack inside the pot, but it doesn’t extend through the glaze so I assume this crack is from first firing? It’s not a small crack. Do you know anything about these pots and whether I should avoid?

orry Beano. I know a little about pots but not enough to help you with this. I assume cracked is cracked and will always be a structural weakness so the pot is much more likely to give way at some stage.

Beano wrote: ↑July 31st, 2020, 9:08 am I’ve found a couple of vintage pots at a shop here. I’m pretty sure they are Chinese and are Guangzhou. Unfortunately both the ones I want are damaged. One had a corner chip and the other more expensive one has a crack inside the pot, but it doesn’t extend through the glaze so I assume this crack is from first firing? It’s not a small crack.

Bonsai Ceramics? I bought one of those vintage pots a little while back, it's lovely. It's currently sitting in my shed waiting for a tree so I can't comment on its robustness. I think I'd personally avoid the one with the crack unless it was priced accordingly; as Neil says it'll always be a weak spot.

Yes that’s the place.


Sent from my iPhone using Tapatalk

I would not bother buying damaged pots. Why waste your money. You will never be happy with them. Can’t show them, if your looking to use them as training pots there are better options. Just buy solid pots give them the old flick with the finger to see they ring true and don’t have any faults under glazes etc...
Cheers
Kirky

Noticed an example this morning . The glaze has not chemically bonded with the clay , water gets between clay and glaze , freezes ( thus expanding) and breaks the weak bond. This can be quite an explosive event .
As to the shape of a pot being important , think of a bottle of water in the freezer ( you were cooling it quickly but forgot ) , the bottle will almost certainly shatter as the last of the liquid turns to ice . A bowl of water will survive because the expansion can take place at the open surface without stressing the walls . The same principle applies to a Bonsai pot .
Got to go and find a replacement pot for that maple !
Cheers
Graham